Is your bilirubin laboratory value within the normal range?

Here you can find out what the bilirubin laboratory value indicates, what normal values are and what deviations mean.

Abstract

• Bilirubin is the yellow-brownish bile pigment
• A distinction is made between direct and indirect bilirubin
• In adults, the normal value is between 0.3 and 1.2 ml/dl
• Elevated bilirubin levels can indicate various liver diseases

What does the value mean? What is it?

Bilirubin is a bile pigment (yellow-brownish) that is produced during the breakdown of the red blood pigment(haemoglobin) and binds to the protein albumin in the blood (in this form it is referred to as indirect bilirubin) and is thus transported to the liver. In the liver, the bond with the albumin is dissolved, resulting in “direct bilirubin”. The bilirubin is then released into the intestine via the bile. A large proportion of it is then excreted in the stool, the rest is either reabsorbed via the intestinal cells or leaves the body via the urine.

If the breakdown and excretion of bilirubin is impaired, e.g. in the case of gallstones or tumors, the concentration of bilirubin in the blood increases. This can cause the skin and eyes to turn yellow (jaundice). If the bile duct is completely blocked, the stool is lighter and the urine darker than usual.

When is bilirubin determined in the blood?

The bilirubin value is examined to check the functions of the liver and bile ducts, to clarify the cause of jaundice or to monitor the treatment of jaundice and underlying diseases.

What are normal values?

The following values are for guidance only. The results may vary between different laboratories. You should therefore always discuss your results with a doctor.

AgeTotal bilirubin (mg/dl)

* Newborns have an elevated bilirubin level for a few days as the liver is not yet fully functional.

The normal range for direct bilirubin is below 0.2 mg/dl for all age groups.
The difference between total bilirubin and direct bilirubin is the indirect bilirubin.

When is the bilirubin level elevated?

There are various factors that can lead to an increase in bilirubin levels. In order to be able to draw conclusions about the cause of the increased value, the proportions of direct and indirect bilirubin are considered.

Possible causes of elevated indirect bilirubin:

• Increased dissolution of red blood cells (hemolysis)
• After extensive burns
• Impaired bilirubin breakdown (e.g. Meulengracht’s disease)

Possible causes of a simultaneous increase in indirect and direct bilirubin are damage to the liver tissue

• Liver inflammation (hepatitis)
• Liver cirrhosis or fatty liver
• Liver cancer or liver metastases
• Poisoning by alcohol, drugs or mushrooms
• Damage to the liver due to medication
• Infections with salmonella or leptospira

Possible causes of elevated direct bilirubin are a backlog of bile in the liver due to a blockage of the bile outflow. Possible triggers for this are

• Narrowing of the bile ducts after inflammation
• Gallstones with narrowing of the bile duct
• Tumors in the bile duct

Values that are too low have no clinical significance.

What to do if the values are elevated?

If the amount of bilirubin in the blood is elevated, you should the cause must be clarified.

If the values are only slightly elevated and there are no symptoms, this is usually an indication of Meulengracht’s disease.

If the values are very high, the concentration of bilirubin in the blood should be reduced quickly. In adults, this is done by treating the cause. In newborns, radiation therapy with ultraviolet light is used for several hours, as the light breaks down the excess bilirubin in the skin.

Sources

• https://flexikon.doccheck.com/de/Bilirubin
• https://www.netdoktor.de/laborwerte/bilirubin/
• https://www.netdoktor.de/laborwerte/bilirubin/erhoeht/
• https://www.internisten-im-netz.de/mediathek/blutbild-erklaerung/bilirubin.html